Pilou,
to my knowledge Windows Voice Access can't print in just any software because it relies entirely on the app's built-in design.
For Voice Access to trigger a print job, the software you are using must do at least one of three things:
- Support standard keyboard shortcuts (like Ctrl + P)
- Have a visible, accessible "Print" button that the AI can read and click
- Be built with standard Windows code structures that allow assistive technologies to "see" and control the menus.

Exactly for that reason, and as you mentioned, to avoid using a paid tier, I started building one on my own with Python and free AI speech-to-text libraries. Unfortunately, it's a closed repository at the moment (it's for my day job, so I can't publish it yet, but hopefully I will be able to in the near future).
If you're interested in AI-driven software development, I can tell you that, as far as I know, there are two major open-source players: "Whisper", published by OpenAI, and "Moonshine". These are the two I've been building my Python project on, and both work pretty well. Note: I was experimenting with 'Faster Whisper', as the name suggests. – it is faster. Here are both repos:

https://github.com/SYSTRAN/faster-whisper

https://github.com/moonshine-ai/moonshine

Cheers!
Gabriel